The paper attempts to show the relationship between sociological fertility “theory” and microeconomic fertility “theory.” It is argued that both conceptualizations are derived from a role-competition model. Differences are more apparent than real, conflicts in the literature arising from differences in style of analysis. Economists emphasize the direct effects of independent variables with intervening variables treated essentially as a standardization measure. Sociologists emphasize the intervening variables, the objective being to account for the gross relationship between independent and dependent variable. The sociological style in fertility research would appear to fit in well with recent research on individual modernity. However, in the absence of a component analysis of modernity, the concept is undefined and unmanageable in any attempt to develop a socioeconomic theory of fertility. A theory-data “confrontation” is displayed for Turkish and Mexican materials.